1. Field of the Invention
The present invention concerns friction clutch cover assemblies, particularly suitable for automotive vehicles, comprising a diaphragm spring in said clutch cover assembly, a clutch release bearing in axial face-to-face relationship with said diaphragm spring, a central hole in said diaphragm spring, and a plurality of centripetal radial fingers around said central hole on which the release bearing is adapted to act in traction through the intermediary of a transverse annular flange disposed within said clutch cover assembly.
2. Description of the Prior Art
As is known, a diaphragm spring of the aforementioned kind is disposed, within a clutch cover assembly, between a cover and a pressure plate, with two annular contact areas of different diameter. It acts, in the so-called rest configuration, in the sense to increase the separation between the cover and the pressure plate. Following the disposition of a friction disk between said pressure plate and a reaction plate attached to the cover, this results in clamping of this friction disk to said reaction plate, which is generally driven by the crankshaft of a motor, so as to rotate therewith; this is the action of engaging the clutch. A release bearing is used to disengage the clutch by acting, in this case in traction, on the diaphragm spring so as to reduce and then eliminate the pressure applied by it to the pressure plate; no longer being clamped between the pressure plate and the reaction plate, the friction disk is no longer driven in rotation.
As is also known, clutch release bearings essentially comprise an operating member adapted to be acted on by a control member, commonly referred to as a yoke, and a drive member adapted to act on the fingers of a diaphragm spring; these components are coupled together in the axial direction by means of a ball bearing, but free to rotate. Conventional clutch release bearings currently divide into two major categories, according to whether they press on the fingers of a diaphragm spring ("push" type release bearings) or pull on same ("pull" type release bearings). In the former case, the release bearing is entirely outside the clutch cover assembly and it is axially positioned opposite the diaphragm spring during the very final stages of mounting the clutch, between the motor and the gearbox in an automotive vehicle, for example.
In the case of pull type release bearings, with which the present invention is concerned, the assembly operations prove more delicate since the operating member of the release bearing is outside the clutch cover assembly, whereas the drive member is partially inside the clutch cover assembly (transverse annular flange) and partially outside it (so that it may be coupled to the operating member), so that there is thus an axial part passing through the central hole in the diaphragm spring in order to join together these two parts. As a result of this, the operations of mounting the release bearing on the one hand and the clutch cover assembly on the other hand must be carried out in parallel, with the result that these parts cannot be transported and/or stored prior to their final mounting between motor and gearbox other than in a pre-assembly configuration. On the one hand, this entails a considerable storage space and on the other hand great caution must be exercised in handling in view of the high risk of damaging the delicate interface between these two parts.
An object of the present invention is to overcome these disadvantages and to provide for the separate assembling and delivery of each of the two parts. The invention is also directed towards a considerable simplification in the operations of assembling a pull type clutch release bearing and to substantially reducing the manufacturing costs thereof.